Temperature and photoperiod responses of soybean embryos culturedin vitro

摘要

Temperature and photoperiod each have direct effects on growth rate of excised embryos of soybean (Glycine max(L.) Merrill). To determine if the effects of photoperiod are altered by temperature, embryos of 'Ransom II' were culturedin vitroat 18, 24, and 30 deg;C under photoperiod durations of 12 and 18ensp;h at an irradiance of 9ensp;Wensp;mminus;2(700 to 850ensp;nm) and a photosynthetic photon flux density of 58ensp;mu;molensp;mminus;2ensp;sminus;1(400 to 700ensp;nm). Accumulation rates of fresh and dry weight were greater under 18-h than 12-h photoperiods over the entire range of temperature. Water content of the cultured embryos was not affected by photoperiod but was greater at 18 and 30 than 24 deg;C. The accumulation rate of dry weight increased from 18 to 26 but declined at 30 deg;C.